Spiralmax

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <000401bdb21f$23438600$34822bd1@486-166> "Ned Ritchie" writes:

> My concern is as I posted to this email list earlier a miss, a stumble, and
> the computer reducing boost can occur from a cone filter.  Guess what it
> will do if you make a tornado inside the air meter?  I don't know but it is
> difficult to make laminar flow with that thing.

Ned,

I'm trying to understand (with some QLCC help) what's happened to John
Robinson's MB ur-quattro.  The MB is a 2226cc relative of the MC,
controlled by a MAC12D - MAC11 with the emission control stuff deleted.

It's all very MC-like.  Single knock sensor, etc., but obviously no
lambda sensor.  The fuel frequency valve duty cycle is calculated -
there's no probe point in the engine compartment, but I've attached
Orin's little duty cycle display direct to Pin 8 and we can see the
duty cycle being varied by the ECU - as high as over 80% in some
short-term situations.

The car behaves normally in the lower gears, gets sluggish approaching
redline in third, and won't get to redline at all in fourth.

He's had some airflow mods made - a K&N, porting, different turbo,
etc., and it's my current theory that the ECU's ignorance of these
is responsible for his problem.  More air, but no more fuel.

Your comment about cone filters interested me, though.  Do you still
have that post, or could you re-iterate the opinion.  It would only
be a matter of an hour or so for me to pop up to John's and reinstall
a conventional paper filter for a test.

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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